This invention relates generally to adjuster mechanisms, and more particularly to a sliding headlamp adjuster mechanism for use in motor vehicles.
In traditional sealed beam style headlamps, the lamp""s aim is adjusted by rotating one or more screws that hold the frame of the lamp to the vehicle. Such adjustment is made from the front of the vehicle by inserting a screwdriver or the like between the lamp frame and the vehicle trim and turning the screws to alter the orientation of the lamp and effectuate the desired adjustment. As the design of motor vehicles has evolved, headlamps have continually been reconfigured to improve the aerodynamics and styling of the front end of the vehicle. Modern headlamps are designed so that their lenses follow the contour of the vehicle to provide an aerodynamically efficient exterior surface. Adjustment of these headlamps must still be performed in order to provide an optimal beam of light and to prevent the aiming of light beams toward oncoming vehicles. Such adjustment is made by moving a reflector within the lamp assembly so that light is directed in the desired manner. Automotive manufacturers""demand for aerodynamically efficient headlamp designs has lead to modular designs where the headlamp adjustment mechanism is located within the interior of the engine compartment and positioned such that adjustment can be easily performed without removing any trim pieces. Thus, the constraints of the installation area and the demands of the automobile manufacturers for aerodynamic headlamp designs dictate the location from which adjustment must be made.
There are many adjuster devices designed for use in connection with aerodynamic headlight designs including, among others, the devices disclosed in U.S. Pat. Nos. 5,707,133 and 5,214,971 to Burton, the inventor of the present invention. Modern automotive headlamp assemblies typically include several basic parts: a support frame, a reflector, a lens, a bulb, and one or more adjusters. The support frame houses the reflector and the bulb on a pivotable mounting to allow the aim of the light to be adjusted using the adjusters and provides a mounting surface for attaching adjusters. The lens seals the front of the support frame to protect it from the elements assailing the front end of the vehicle and provides an aerodynamic shape and attractive appearance. The reflector mounts on one fixed ball joint and is adjustable horizontally and vertically using adjusters that interface with the reflector through moving ball joints. The moving ball joints are moved by actuating the adjusters connected to the moving ball joints by a ball stud. Geared angle style adjusters, such as the ones disclosed in the referenced Burton patents, are often used to adjust the aim of the headlamp. However, such devices are designed to allow adjustment of the headlamp from a location behind the assembly, typically from within the engine compartment and immediately behind and above the lamp assembly. Accordingly, such devices cannot be effectively used in vehicles where the area immediately behind and above the lamp assembly is not accessible. One such vehicle design is shown in FIG. 14. In that design, the vehicle fender 20 covers the headlamp assembly 22 rendering the area behind and above the assembly substantially inaccessible without removal of the fender 20 of the vehicle. The area below the headlamp assembly 22 is similarly inaccessible because of the bumper 21 and other vehicle components. Thus, existing geared angle style headlamp adjusters have not been found to be effective for use in such vehicle designs.
Conventionally in a vehicle such as the one shown in FIG. 14, a sealed beam style headlamp is used. However, due to consumer and vehicle manufacturer styling preferences and performance objectives, it is desirable to use a reflector style headlamp in such vehicles. The conventional method for adjusting sealed beam lamps cannot be used to adjust a reflector style lamp and the area immediately above and behind the lamp is inaccessible such that a conventional geared angle style adjuster cannot be used. Accordingly, a need exists for a headlamp adjuster which can be used in connection with a vehicle design where the area behind and above the lamp assembly is substantially inaccessible and the use of a reflector style lamp is desired.
The present invention relates to a sliding headlamp adjuster that allows for precise adjustment control, can be used where the area above and behind the lamp assembly is inaccessible, ensures smooth operation, can include a vehicle headlamp aiming device (xe2x80x9cVHADxe2x80x9d), is cost effective, and which solves the problems raised or not solved by existing headlamp adjuster designs. As described in more detail below and shown in the accompanying drawings, the sliding headlamp adjuster uses a two-piece sliding body construction to meet these objectives.
A headlamp adjuster in accordance with one embodiment of the present invention includes a base housing with a slide disposed at least partially therein. The base housing includes one or more mounting tabs such that the adjuster can be mounted to the back of a headlamp assembly support frame. The base housing has channels along its sides in which rails extending from the slide are disposed. A ball stud is threaded into the slide and protrudes therefrom passing through the base housing into the headlamp assembly. The ball of the ball stud is engaged in a socket in the reflector so that axial movement of the ball stud causes movement of the reflector. The ball stud is caused to axially move by a corresponding sliding of the slide along the channels in the base. Movement of the slide results from rotation of an adjustment screw that is threaded into the sliding piece but held in axial position (free to rotate) in the base. Thus, rotation of the axially-fixed adjustment screw causes movement of the slide and the ball stud with respect to the base housing. Because the base is fixed to the headlamp assembly support frame and the ball is engaged in a socket in the reflector, rotation of the adjusting screw causes changes in the orientation of the reflector within the assembly and the aim of the lamp is thereby adjusted.
In certain applications, the adjuster must include a VHAD. U.S. National Highway Traffic Safety Administration (xe2x80x9cNHTSAxe2x80x9d) standards require that horizontal adjuster mechanisms be either non-readjustable after the proper aim has been achieved or be equipped with a non-recalibratable VHAD. Currently, VHADs are required for horizontal adjusters but not for vertical adjusters. The VHAD used in the sliding adjuster includes an indicator plate with a post extending therefrom. The post includes a groove with a partial helical twist and is axially fixed (free to rotate) with respect to the base housing. A tab jutting from the slide is disposed in the groove. The indicator plate is positioned on the base near the adjustment screw such that indicator lines on the plate can be seen by the person adjusting the aim of the lamp. The base includes aiming rails behind the plate that, in connection with the indicator lines, allow the person making the adjustment to perceive how much of an adjustment has been made. Because the groove includes a partial helical twist, as the tab jutting from the slide moves along the groove with movement of the slide, the post and indicator plate are caused to rotate. The scale of the movement of the plate as reflected in the indicator lines is designed to reflect the corresponding movement of the reflector. If no VHAD is required, the indicator plate and post are simply not installed in the sliding adjuster.
The new design has numerous benefits that make it advantageous for use in connection with reflector style headlamps. The new design allows precise control of reflector aim, has smooth operational characteristics, can include a VHAD, and effectively maintains adjustment. Further, the new adjuster can be used where the area above and behind the lamp is inaccessible and it is cost effective to manufacture and install.
While the present invention is particularly useful in automotive headlamp assemblies, other applications are certainly possible and references herein to use in a headlamp assembly should not be deemed to limit the application of the present invention. Rather, the present invention may be advantageously adapted for use where similar performance capabilities and characteristics are desired. These and other objects and advantages of the present invention will become apparent from the detailed description, claims, and accompanying drawings.